• Earthquakes and Structures
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• 제12권4호
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• pp.457-468
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• 2017

When studying the vibration of a suspension bridge based on the traffic-bridge coupled system, most researchers ignored the contribution of the pavement response. For example, the pavement was simplified as a rigid base and the deformation of pavement was ignored. However, the action of deck pavement on the vibration of vehicles or bridges should not be neglected. This study is mainly focused on establishing a new methodology fully considering the effects of bridge deck pavement, probabilistic traffic flows, and varied road roughness conditions. The bridge deck pavement was modeled as a boundless Euler-Bernoulli beam supported on the Kelvin model; the typical traffic flows were simulated by the improved Cellular Automaton (CA) traffic flow model; and the traffic-pavement-bridge coupled equations were established by combining the equations of motion of the vehicles, pavement, and bridge using the displacement and interaction force relationship at the contact locations. The numerical studies show that the proposed method can more rationally simulate the effect of the pavement on the vibrations of bridge and vehicles.

• 대한교통학회:학술대회논문집
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• 대한교통학회 1995년도 제27회 학술발표회
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• pp.84-98
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• 1995

Network-based model were developed to predict short term future traffic volume based on current traffic, historical average, and upstream traffic. It is presumed that upstream traffic volume can be used to predict the downstream traffic in a specific time period. Three models were developed for traffic flow prediction; a combination of historical average and upstream traffic, a combination of current traffic and upstream traffic, and a combination of all three variables. The three models were evaluated using regression analysis. The third model is found to provide the best prediction for the analyzed data. In order to balance the variables appropriately according to the present traffic condition, a heuristic adaptive weighting system is devised based on the relationships between the beginning period of prediction and the previous periods. The developed models were applied to 15-minute freeway data obtained by regular induction loop detectors. The prediction models were shown to be capable of producing reliable and accurate forecasts under congested traffic condition. The prediction systems perform better in the 15-minute range than in the ranges of 30-to 45-minute. It is also found that the combined models usually produce more consistent forecasts than the historical average.

• 한국안전학회지
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• 제25권2호
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• pp.78-83
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• 2010

An installation of automated speed enforcement system(ASES) was known for traffic safety and accident preventive effects that traffic characteristics transmute by speed distribution stabilizing. This study is verified the variations of average speed, 85% speed, speed distribution and dispersion as traffic characteristics depend on enforcement system influences in the road. We tested selected 5 areas. By and large, it has a little differences depend on road geometric structure and traffic environment but that is not too much. After all, after automated speed enforcement system installed in all of test areas, average speed, 85% accumulated speed, speed distribution and dispersion characteristics were declined and equalized. The speed dispersion was smaller than before installed the ASES. The speed dispersion value of each case that is the limited speed has been 70Km/h, 80Km/h at flat and straight, 80Km/h at downhill and straight or downhill and left-curved area was 77.3%, 65.2%, 68.7% and 54.1%. Each of the data was declined. We could analyze that average speed distributed depletion factor was declined rapidly by 66.3% in test area.

• 한국군사과학기술학회지
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• 제12권2호
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• pp.213-221
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• 2009

An aircraft collision accident is a disaster that causes great losses of inventories and lives. Though a collision avoidance warning function is provided automatically to pilots in the aircrafts by the enhancement of the aircraft capability, achieving fast decision-making to escape a collision situation is a complex and dangerous work for pilots. If an in-flight collision situation is controlled by the air traffic control system which monitors all airplanes in the air, it would be more efficient to prevent in-flight collisions because it can handle the emergency before the pilot's action. In this paper, we develop the collision avoidance warning function in the air traffic control system. Specifically, we design and implement the five stages of the collision avoidance function, and propose a visualization method which could effectively provide the operators with the trajectories and altitudes of the aircrafts in a collision situation. By developing an in-flight collision warning function in the air traffic control system that visualizes flight patterns through the state transition data of in-flight aircrafts on the flight path lines, it can effectively prevent in-flight collisions with traffic alerts. The developed function allows operators to effectively select and control the aircraft in a collision situation by providing the operators with the expected collision time, the relative distance, and the relative altitude while assessing the level of alert, and visualizing the alert information which includes the Attention-Warning-Alert phase via embodying the TCAS standard. With the developed function the air traffic control system could sense an in-flight collision situation before the pilot's decision-making moment.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 춘계학술대회 논문집
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• pp.197-204
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• 2005

1983년에 교통안전특정해역으로 설정되어 운영 중인 여수 ${\cdot}$ 광양항은 부산항과 더불어 동북아 중심항만(Hub Port)으로서 향후 2011년까지 총 33개의 컨테이너 선석 둥이 개발 추진 중에 있다. 또한 해상교통량이 급격히 긍가하고 있으며, 선박의 대형화, 고속화로 인하여 대형사고의 발생우려가 상존하는 지역이다. 본 연구에서는 여수 ${\cdot}$ 광양항의 미래 지향적인 안전한 해상교통환경을 조성하기 위한 체계적이고 종합적인 선박안전운항 방안을 마련하기 위해서 여수 ${\cdot}$ 광양항 입출항 항로에 대한 해상교통환경을 면밀히 분석 ${\cdot}$ 평가하여 해양사고 예방을 위한 종합적인 해상교통안전체제 구축에 필요한 문제점을 도출한다.

• 정보처리학회논문지B
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• 제15B권6호
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• pp.543-552
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• 2008

ATIS(Advanced Traveler Information System)는 교통 상황이나 주행 정보 등을 실시간으로 제공하여 이용자의 편익을 도모하는 시스템이다. ATIS를 위해 영상 이미지를 분석하여 교통정보를 수집 수집하는 방식은 크게 영역에 루프 검지기를 설정하여 측정하는 방식과, 영상 분석을 통해 차량을 검출하고 추적하는 방식으로 나뉜다. 본 연구에서는 차선마다 가상 검지기를 설치하는 방식을 기초로, 영상 분석 방법의 차량 위치 추적 방식을 응용하여 교통정보를 측정하는 시스템을 제안한다. 이때 가상 검지기 방식의 단점을 보완하기 위해 차선마다 다중의 가상 검지선을 설정하여, 검지 영역 내에 여러 대의 차량이 진입하거나 차량의 차선 변경 시에도 효과적으로 교통정보를 추출할 수 있게 하였고, 영상분석 방식의 문제점인 검지영역의 크기 증가에 따른 차량 추출 시간의 증가를 해결하기 위해 검지 영역 내에서 대표 픽셀을 추출하여 교통정보를 측정하였다. CCTV를 이용하여 취득한 영상에 제안하는 시스템을 이용하여 차량의 평균 속도와 차선별 교통량 측정한 결과 실제 교통량대비 평균 92.32%의 차량 검지율를 보였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.236-246
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• 2003

This paper is implemented a control algorithm in order to be stable and minimized to entire train traffic system at delayed case. Signal ing system is described wi th algebraic equations given for train headway, Discrete-event simulation principles are reviewed and a demonstration block signaling model using the technique is implemented. Train congestion at station entrance for short headway operation is demonstrated and the propagation of delays along a platform of trains from any imposed delay to the leading train is also shown. A rail way signaling system is by nature a distributed operation with event triggered at discrete intervals. Although the train kinematic variables of position, velocity, and acceleration are continually changing, the changes are triggered when the trains pass over section boundaries and arrive at signals and route switches. This paper deals with linear-mode1ing, stability and optimal control for the traffic on such metro line of the model is reconstructed in order to adapt the circuits. This paper propose optimal control laws wi th state feedback ensuring the stability of the modeled system for circuits. Simulation results show the benefit to be expected from an efficient traffic control. The main results are summarized as follows: 1. In this paper we develop a linear model describing the traffic for both loop lines, two state space equations have been analyzed. The first one is adapted to the situation where a complete nominal time schedule is available while second one is adapted when only the nominal time interval between trains is known, in both cases we show the unstability of the traffic when the proceeding train is delayed following properties, - They are easily implemented at law cost on existing lines. - They ensure the exponetial stability of loop system. 2. These control laws have been tested on a traffic simulation software taking into the non-linearites and the physical constraints on a metro line. By means of simulation, the efficiency of the proposed optimal control laws are shown.

• 한국항해항만학회지
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• 제37권6호
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• pp.581-586
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• 2013

완도군을 중심으로 한 서남 해안권 해상교통의 수요는 나날이 증가하고 있다. 그러나 이 같이 증가하는 여객과 관광수요에 대응할 수 있는 해상 안전 및 편의 시설 개선을 매우 미흡한 실정이다. 본 연구에서는 완도항 항만수역, 완도권내 통항 항로 그리고 여객선 운항 환경등에 대한 현황을 조사 분석하였다. 이와 함께 완도권 해상교통을 이용하는 이용자들을 대상으로 여객선 운항 환경 개선에 대한 설문을 수행하였다. 이를 바탕으로 해당 해역의 항해 위해도를 조사 분석하였으며, 여객선 운항 환경을 개선할 수 있는 제도적 장치 중에서 여객선 운임 체제개선, 타 시도 지역과 비교를 통항 개선방안 등을 제안하였다. 가장 시급한 문제는 항로상 산재해 있는 어장과 그로 인해 좁아진 항로가 여객선 운항에 가장 큰 위험요소가 됨을 알 수 있었다. 또한 여객선 운영측면에서는 타 지역에 비하여 자동화물비가 비싸 개선이 필요한 것으로 조사되었다.

• 한국지리정보학회지
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• 제25권1호
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• pp.1-15
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• 2022

자율주행차를 신뢰하고 이용하기 위해서는 도로에서의 안전한 주행이 보장되어야 한다. 이를 위해 최우선으로 갖추어야 할 자율주행 인프라는 교통안전시설이다. 한편 도로에서는 Level 3 수준의 자율주행차와 일반 자동차가 혼재하여 주행하고 있기 때문에 기존에 존재하고 있는 일반 교통안전시설의 관리도 추가로 필요하다. 따라서 본 연구에서는 자율주행 인프라 기반 교통안전시설 현장관리 체계를 연구하고, 이를 기반으로 실증지역(판교)를 선정하여(판교) 현장관리 시험시스템을 구현하였다. 시험시스템 구성은 GNSS(Global Navigation Satellite System) 수신기, 현장관리 단말기, 현장관리 App(Application) 등으로 구성하였으며, 현장 실증 결과 도심지에서도 손쉽게 교통안전시설 정보를 송수신하였고, 교통안전시설에 대하여 효율적으로 운영관리 할 수 있음을 확인하였다. 금번 연구결과는 향후 자율주행 인프라의 지자체 확산 및 인프라 구축에 참고자료로 활용될 것으로 기대한다.

• 한국대기환경학회지
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• 제9권1호
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• pp.93-100
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• 1993

This study was carried out to investigate the relationship between the traffic signal systmes and the air pollutants emitted by the motor vehicles at Kangnam Intersection. One of the most important measures of effectiveness (MOE) in traffic studies is the delay to vehicles in the system. Delay represents indirect costs to the motorist in terms of time loss and a direct cost in terms of fuel consumption during idling. The results of TRANSYT-7F modeling was correlated among delay, fuel consumption and total travel tiem. Air pollutants emission rate can be calculated by the results of modeling and the Korean type emission factor. As expected the highest emissions, for air pollutants, are observed during the morning rush hours (07 : 00-10 : 00). For better results of modeling, the TRANSYT-7F model needs to modify for the Korean type of traffic model. The results of this study indicate that the variation of air pollutants emission rates were closely related to the traffic signal system.